Transmission of Information in a Wireless Communication System

ABSTRACT

Methods, devices, and systems for the transmission of information in a wireless communication system are disclosed. In one embodiment, a method of transmission in a wireless communication system comprises determining by a wireless device ( 201 ) a configuration of a plurality of power amplifiers ( 207 ) to achieve a single antenna transmission mode; amplifying a signal by said wireless device ( 201 ) using the configuration of the plurality of power amplifiers ( 207 ) to form a plurality of amplified signals; simultaneously transmitting at or about the same time by the wireless device ( 201 ) to a base station ( 202 ) the plurality of amplified signals from a plurality of physical antennas ( 212 ), wherein the plurality of physical antennas ( 212 ) are coupled to the configuration of the plurality of power amplifiers ( 207 ); and wherein the measured transmit power from the totality of the plurality of physical antennas ( 212 ) is about the same as the required transmit power using the single antenna transmission mode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.U.S. 61/258,934 filed Nov. 6, 2009, entitled “TRANSMISSION OF CONTROLINFORMATION IN A WIRELESS COMMUNICATION SYSTEM;” U.S. Non-ProvisionalApplication No. U.S. Ser. No. 12/860,624 filed Aug. 20, 2010, entitled“TRANSMISSION OF CONTROL INFORMATION IN A WIRELESS COMMUNICATIONSYSTEM;” and PCT Application No. PCT/US 2010/046,213 filed Aug. 20,2010, entitled “TRANSMISSION OF CONTROL INFORMATION IN A WIRELESSCOMMUNICATION SYSTEM.” The foregoing applications are incorporatedherein by reference in their entirety.

FIELD

The invention generally relates to wireless communication systems and inparticular to the transmission of information in a wirelesscommunication system.

BACKGROUND

Wireless communication systems are widely deployed to provide, forexample, a broad range of voice and data-related services. Typicalwireless communication systems include multiple-access communicationnetworks that allow users to share common network resources. Examples ofsuch networks are time division multiple access (“TDMA”) systems, codedivision multiple access (“CDMA”) systems, single carrier frequencydivision multiple access (“SC-FDMA”) systems, orthogonal frequencydivision multiple access (“OFDMA”) systems, and other like systems. AnOFDMA system is supported by various technology standards such asevolved universal terrestrial radio access (“E-UTRA”), Wi-Fi, worldwideinteroperability for microwave access (“WiMAX”), ultra mobile broadband(“UMB”), and other similar systems. Further, the implementations ofthese systems are described by specifications developed by variousindustry standards bodies such as the third generation partnershipproject (“3GPP”) and 3GPP2.

As wireless communication systems evolve, more advanced networkequipment is introduced that provide improved features, functionality,and performance. A representation of such advanced network equipment mayalso be referred to as long-term evolution (“LTE”) equipment orlong-term evolution advanced (“LTE-A”) equipment. LTE is the next stepin the evolution of high-speed packet access (“HSPA”) with higheraverage and peak data throughput rates, lower latency, and a better userexperience especially in high-demand geographic areas. LTE accomplishesthis higher performance with the use of broader spectrum bandwidth,OFDMA and SC-FDMA air interfaces, and advanced antenna methods.

Communications between wireless devices and base stations may beestablished using single-input, single-output systems (“SISO”), whereonly one antenna is used for both the receiver and transmitter;single-input, multiple-output systems (“SIMO”), where multiple antennasare used at the receiver and only one antenna is used at thetransmitter; and multiple-input, multiple-output systems (“MIMO”), wheremultiple antennas are used at the receiver and transmitter. Compared toa SISO system, a SIMO system may provide increased coverage while a MIMOsystem may provide increased spectral efficiency and higher datathroughput if the multiple transmit antennas, multiple receive antennasor both are utilized. Further, uplink (“UL”) communication refers tocommunication from a wireless device to a base station. Downlink (“DL”)communication refers to communication from a base station to a wirelessdevice.

In 3rd Generation Partnership Project; Technical Specification GroupRadio Access Network; Physical Channels and Modulation (Release 8),3GPP, 3GPP TS 36.211 (“LTE Release 8”), the use of a single antenna issupported for UL transmission that employs SC-FDMA. In 3rd GenerationPartnership Project; Technical Specification Group Radio Access Network;Further Advancements For E-UTRA; Physical Layer Aspects (Release 9),3GPP, 3GPP TR 36.814 V9.0.0 (2010-03) (“LTE-A Release 10”), multipleantennas may be used to improve UL performance by, for instance, the useof transmit diversity and spatial multiplexing. Various transmitdiversity schemes may be used such as space frequency block coding(“SFBC”), space time block coding (“STBC”), frequency switched transmitdiversity (“FSTD”), time switched transmit diversity (“TSTD”),pre-coding vector switching (“PVS”), cyclic delay diversity (“CDD”),space code transmit diversity (“SCTD”), orthogonal resource transmission(“ORT”), and other similar approaches.

BRIEF DESCRIPTION OF THE DRAWINGS

In order for this disclosure to be understood and put into practice byone having ordinary skill in the art, reference is now made to exemplaryembodiments as illustrated by reference to the accompanying figures.Like reference numbers refer to identical or functionally similarelements throughout the accompanying figures. The figures along with thedetailed description are incorporated and form part of the specificationand serve to further illustrate exemplary embodiments and explainvarious principles and advantages, in accordance with this disclosure,where:

FIG. 1 illustrates an example of a wireless communication system.

FIG. 2 is a block diagram of one embodiment of a wireless communicationsystem using a control channel structure in accordance with variousaspects set forth herein.

FIG. 3 illustrates an exemplary uplink channel structure that can beemployed in a wireless communication system.

FIG. 4 is a block diagram of an exemplary system that facilitates thetransmission of information.

FIG. 5 is a block diagram of an exemplary system that facilitates thetransmission of information using transmit diversity.

FIG. 6 is a block diagram of another exemplary system that facilitatesthe transmission of information.

FIG. 7 is a block diagram of one embodiment of a wireless transmissionsystem using a transmit diversity scheme with various aspects describedherein.

FIG. 8 illustrates multiple embodiments of an orthogonal resourcemapping method used to perform transmit diversity in a wirelesscommunication system with various aspects described herein.

FIG. 9 illustrates another embodiment of an orthogonal resource mappingmethod used to perform transmit diversity in a wireless communicationsystem with various aspects described herein.

FIG. 10 illustrates another embodiment of an orthogonal resource mappingmethod used to perform transmit diversity in a wireless communicationsystem with various aspects described herein.

FIG. 11 illustrates another embodiment of an orthogonal resource mappingmethod used to perform transmit diversity in a wireless communicationsystem with various aspects described herein.

FIG. 12 illustrates one embodiment of an orthogonal resource mappingmethod using reserved control channel elements (“CCE”) to performtransmit diversity in a wireless communication system with variousaspects described herein.

FIG. 13 illustrates another embodiment of an orthogonal resource mappingmethod used to perform transmit diversity in a wireless communicationsystem with various aspects described herein.

FIG. 14 illustrates another embodiment of an orthogonal andquasi-orthogonal resource mapping method used to perform transmitdiversity in a wireless communication system with various aspectsdescribed herein.

FIG. 15 illustrates one embodiment of a method for configuring wirelessdevices for transmit diversity in a wireless communication system withvarious aspects described herein.

FIG. 16 illustrates another embodiment of an orthogonal resource mappingmethod used to perform transmit diversity in a wireless communicationsystem with various aspects described herein.

FIG. 17 illustrates another embodiment of an orthogonal resource mappingmethod used to perform transmit diversity in a wireless communicationsystem with various aspects described herein.

Skilled artisans will appreciate that elements in the accompanyingfigures are illustrated for clarity, simplicity and to further improveunderstanding of the exemplary embodiments, and have not necessarilybeen drawn to scale.

DETAILED DESCRIPTION

Although the following discloses exemplary methods, devices, and systemsfor use in wireless communication systems, it will be understood by oneof ordinary skill in the art that the teachings of this disclosure arein no way limited to the exemplary embodiments shown. On the contrary,it is contemplated that the teachings of this disclosure may beimplemented in alternative configurations and environments. For example,although the exemplary methods, devices, and systems described hereinare described in conjunction with a configuration for E-UTRA systems,which is the air interface of the 3GPP organization's LTE upgrade pathfor mobile networks, those of ordinary skill in the art will readilyrecognize that the exemplary methods, devices, and systems may be usedin other wireless communication systems and may be configured tocorrespond to such other systems as needed. Accordingly, while thefollowing describes exemplary methods, devices, and systems of usethereof, persons of ordinary skill in the art will appreciate that thedisclosed exemplary embodiments are not the only way to implement suchmethods, devices, and systems, and the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

Various techniques described herein can be used for various wirelesscommunications systems. The various aspects described herein arepresented as systems that can include a number of components, devices,elements, members, modules, peripherals, or the like. Further, thesesystems can include or not include additional components, devices,elements, members, modules, peripherals, or the like. In addition,various aspects described herein can be implemented in hardware,firmware, software or any combination thereof. It is important to notethat the terms “network” and “system” can be used interchangeably.Relational terms described herein such as “above” and “below,” “left”and “right,” “first” and “second,” and the like may be used solely todistinguish one entity or action from another entity or action withoutnecessarily requiring or implying any actual such relationship or orderbetween such entities or actions. The term “or” is intended to mean aninclusive “or” rather than an exclusive “or.” Further, the terms “a” and“an” are intended to mean one or more unless specified otherwise orclear from the context to be directed to a singular form.

Wireless communication networks consist of a plurality of wirelessdevices and a plurality of base stations. A base station may also becalled a node-B (“NodeB”), a base transceiver station (“BTS”), an accesspoint (“AP”), or some other equivalent terminology. A base stationtypically contains one or more radio frequency (“RF”) transmitters andreceivers to communicate with wireless devices. Further, a base stationis typically fixed and stationary. For LTE and LTE-A equipment, the basestation is also referred to as an E-UTRAN NodeB (“eNB”).

A wireless device used in a wireless communication system may also bereferred to as a mobile station (“MS”), a terminal, a cellular phone, acellular handset, a personal digital assistant (“PDA”), a smartphone, ahandheld computer, a desktop computer, a laptop computer, a tabletcomputer, a set-top box, a television, a wireless appliance, or someother equivalent terminology. A wireless device may contain one or moreRF transmitters and receivers, and one or more antennas to communicatewith a base station. Further, a wireless device may be fixed or mobileand may have the ability to move through a wireless communicationsystem. For LTE and LTE-A equipment, the wireless device is alsoreferred to as user equipment (“UE”).

FIG. 1 is a block diagram of a system 100 for wireless communication. InFIG. 1, system 100 can include one or more wireless devices 101communicatively linked with one or more base stations 102. Wirelessdevice 101 can include a processor 103 coupled to a memory 104, aninput/output device 105, a transceiver 106, or any combination thereof,which can be utilized by wireless device 101 to implement variousaspects described herein. Transceiver 106 of wireless device 101 caninclude one or more transmitters 107 and one or more receivers 108.Further, associated with wireless device 101, one or more transmitters107 and one or more receivers 108 can be connected to one or moreantennas 109.

Similarly, base station 102 can include a processor 121 coupled to amemory 122, and a transceiver 123, which can be utilized by base station102 to implement various aspects described herein. Transceiver 123 ofbase station 102 can include one or more transmitters 124 and one ormore receivers 125. Further, associated with base station 102, one ormore transmitters 124 and one or more receivers 125 can be connected toone or more antennas 128.

Base station 102 can communicate with wireless device 101 on the ULusing one or more antennas 109 and 128, and on the DL using one or moreantennas 109 and 128, associated with wireless device 101 and basestation 102, respectively. Base station 102 can originate DL informationusing one or more transmitters 124 and one or more antennas 128, whereit can be received by one or more receivers 108 at wireless device 101using one or more antennas 109. Such information can be related to oneor more communication links between base station 102 and wireless device101. Once information is received by wireless device 101 on the DL,wireless device 101 can process the received information to generate aresponse relating to the received information. Such response can betransmitted back from wireless device 101 on the UL using one or moretransmitters 107 and one or more antennas 109, and received at basestation 102 using one or more antennas 128 and one or more receivers125.

In accordance with one aspect, the wireless communication of controlinformation can be conducted using a wireless communication system suchas a system 200 as illustrated in FIG. 2. In one embodiment, system 200illustrates a control signaling structure that can be employed in asystem using LTE or LTE-A equipment or another appropriate wirelesscommunication technology. System 200 can include a wireless device 201communicatively linked with a base station 202. Wireless device 201 caninclude a processor 203 coupled to a memory 204, an input/output device205, a transceiver 206, and a control information processor 209.Transceiver 206 of wireless device 201 can include one or moretransmitters 207 and one or more receivers 208. Transmitter 207 andreceiver 208 both of wireless device 201 can be coupled to antenna 212.Base station 202 can include a processor 221 coupled to a memory 222, atransceiver 223, and a control information processor 226. Transceiver223 of base station 202 can include one or more receivers 224 and one ormore transmitters 225. Transmitter 225 and receiver 224 both of basestation 202 can be coupled to antenna 228.

As shown in FIG. 2, UL control signaling can be carried on, forinstance, a physical uplink control channel (“PUCCH”) 230 or a physicaluplink shared channel (“PUSCH”) 231. UL data can be carried on, forinstance, a PUSCH 231. DL control signaling can be carried on, forinstance, a physical downlink control channel (“PDCCH”) 232, and DL datacan be carried on, for instance, a physical downlink shared channel(“PDSCH”) 233.

In one embodiment, control information processor 226 of base station 202can generate or otherwise obtain data, control information, or otherinformation intended for wireless device 201. The control informationcan then be originated on PDCCH 232 and data can be transmitted on PDSCHusing transmitter 225 and antenna 228 of base station 202, where antenna212 and receiver 208 at wireless device 201 can receive it. Onceinformation is received by wireless device 201 on the DL, controlinformation processor 209 of wireless device 201 can process thereceived information to generate a response relating to the receivedinformation.

Such response can then be transmitted back to base station 202 on PUCCH230, or on PUSCH 231 when, for instance, the PUSCH resource isallocated. Such response can be transmitted using transmitter 207 andantenna 212 of wireless device 201 and received at base station 202using receiver 224 and antenna 228. Once information is received by basestation 202 on the UL, control information processor 226 of base station202 can process the received information to generate a response relatingto the received information, and facilitate transmission of anygenerated control information on the DL to wireless device 201.

In another embodiment, control information processor 209 of wirelessdevice 201 can generate UL control information, including anacknowledgement (“ACK”) for correctly received data, a negativeacknowledgement (“NAK”) for incorrectly received data or both; channelquality information (“CQI”), such as channel quality indications,precoding matrix index (“PMI”), or rank indicator (“RI”); or any otherinformation. ACK/NAK can be transmitted using PUCCH format 1a/1b, andCQI can be transmitted using PUCCH format 2/2a/2b. PUCCH format 1 can beused by wireless device 201 for a scheduling request. PUCCH format1/1a/1b can share the same structure as persistent and dynamic ACK/NAK.PUCCH format 2/2a/2b can be used for CQI and concurrent transmission ofCQI and ACK/NAK.

The communication of control information in a wireless communicationsystem can use an exemplary structure 300 as illustrated in FIG. 3. InFIG. 3, structure 300 illustrates an UL control channel structure thatcan be employed in a system using LTE or LTE-A equipment or anotherappropriate wireless communication technology. In structure 300, oneframe 301 can include twenty slots 303 of 0.5 msec duration each, andone sub-frame 302 can include two slots 303. Each slot 303 can carry sixor seven SC-FDMA symbols in the time domain, depending on the type ofcyclic prefix used, and may include twelve sub-carriers in the frequencydomain in each resource block (“RB”). In the exemplary, normal cyclicprefix is used, and as such, seven SC-FDMA symbols can be transmitted ineach RB. It is important to recognize that the claimed subject matter isnot limited to this particular channel structure.

Referring to FIG. 3, an exemplary of several RBs 305 is shown. As aperson of ordinary skill in the art would appreciate, RB 305 is atime-frequency allocation that is assigned to a wireless device and canbe defined as the smallest unit of resource allocation by the basestation. Further, RB 305 may extend across a plurality of slots 303. TheLTE UL may allow for a very high degree of flexibility allowing for anynumber of uplink RBs 305 ranging, for instance, from a minimum of sixRBs 305 to a maximum of one hundred RBs 305. RB 305 can be comprised ofa plurality of resource elements (“RE”) 304, which can represent asingle sub-carrier in frequency for a time period of one symbol.

FIG. 4 is a block diagram of an exemplary system 400 that facilitatestransmission of control information in a wireless communication system.In system 400, a message can be input to a modulator 401. Modulator 401,for instance, may apply quadrature phase shift keying (“QPSK”)modulation, binary phase shift keying (“BPSK”), or any other form ofmodulation. The modulated symbols are then input to a spreading logic402. An index is also input to spreading logic 402 and used to select anorthogonal resource 405, which is composed of a first spreading sequence406 a and a second spreading sequence 406 b. Spreading logic 402 appliesfirst spreading sequence 406 a and second spreading sequence 406 b tothe modulated symbols. Such two one-dimensional (“1-D”) spreadingsequences could also be calculated or generated and stored in temporaryor permanent memory as two-dimensional (“2-D”) spreading sequences, eachcorresponding to an index. Such 2-D spreading sequences could be appliedto modulated symbols to perform the spreading operation. In one example,one of the spreading sequences can be a Zadoff-Chu sequence while theother spreading sequence can be an orthogonal cover sequence. Themodulated symbols after spreading are input to a transmitter 403 fortransmission using an antenna 404 to, for instance, a base station.

Spatial orthogonal transmit diversity (“SORTD”), which may also bereferred to as space coding transmit diversity (“SCTD”), and whosegeneral principles are described in 3GPP document R1-091925, Evaluationof transmit diversity for PUCCH in LTE-A, Nortel, 3GPP TSG-RAN WG1 #57,San Francisco, US, May 4-8, 2009, may be applied to modulated messagesfor improved communication performance while maintaining low peak toaverage power ratio (“PAPR”) when the transmit diversity system usesmultiple antennas. One of ordinary skill in the art will appreciate theneed to maintain a low PAPR of a SC-FDMA transmission. The wirelesstransmission of information can be conducted using a transmit diversityscheme such as an exemplary system 500 as illustrated in FIG. 5. In FIG.5, system 500 describes a SORTD scheme that can be employed in awireless communication system.

Referring to FIG. 5, a message is input to a modulator 501. Modulator501, for instance, may apply quadrature phase shift keying (“QPSK”)modulation, binary phase shift keying (“BPSK”), or any other form ofmodulation. The modulated symbols can be input to spreading logic 502 aand 502 b. Each modulated symbol can be spread in both of spreadinglogic 502 a and 502 b. A first index and a second index can be input tospreading logic 502 a and 502 b for selection of orthogonal resources505 a and 505 b, respectively. First orthogonal resource 505 a iscomposed of first spreading sequence 506 a and second spreading sequence506 b, or a pre-calculated or a concurrently-generated combinedspreading sequence comprising first spreading sequence 506 a combinedwith second spreading sequence 506 b. Second orthogonal resource 505 bis composed of third spreading sequence 506 c and fourth spreadingsequence 506 d, or a pre-calculated or concurrently-generated combinedspreading sequence comprising third spreading sequence 506 c combinedwith fourth spreading sequence 506 d.

In FIG. 5, spreading logic 502 a can apply first spreading sequence 506a and second spreading sequence 506 b to the modulated symbols, or canapply the pre-calculated or concurrently-generated combined spreadingsequence including first spreading sequence 506 a combined with secondspreading sequence 506 b. In parallel, spreading logic 502 b can applythird spreading sequence 506 c and fourth spreading sequence 506 d tothe modulated symbols, or can apply the pre-calculated orconcurrently-generated combined spreading sequence comprising thirdspreading sequence 506 c combined with fourth spreading sequence 506 d.The modulated symbols after spreading can be input to transmitters 503 aand 503 b and transmitted via antennas 504 a and 504 b, respectively.The signals transmitted from antennas 504 a and 504 b can superpose eachother in the air. A base station can receive the transmitted messageusing an antenna and a receiver. Since the base station can know apriori the orthogonal resources 505 a and 505 b applied to the modulatedmessage transmitted from each antenna 504 a and 504 b, the base stationcan separate each modulated message by using the same orthogonalresources 505 a and 505 b.

A PDCCH can be transmitted on an aggregation of one or more CCEs. CCEs,when used as control channel elements, are the minimum unit for carryinga downlink message such as a PDCCH. A PDCCH can be assigned using one ormore CCEs in order to provide the PDCCH with a code rate correspondingto the quality of the wireless communication between a base station anda wireless device. The format of the PDCCH can be determined accordingto, for instance, the payload size of the control information, the coderate, and the assigned number of CCEs. A plurality of PDCCHs may betransmitted in a single subframe in a specific control region, whichnormally occupies the first one or several OFDM symbols. A wirelessdevice can monitor the control region of every subframe and can attemptto find its corresponding PDCCH by, for instance, blind decoding overCCEs in designated or predetermined search spaces. In LTE Release 8, theindex of an orthogonal resource for spreading an uplink ACK/NAK messagecan be derived from the first CCE in the PDCCH in which thecorresponding PDSCH is scheduled. Such index can be derived using, forinstance, the location of the corresponding CCE.

The wireless transmission of control information can be conducted usinga transmit diversity scheme such as an exemplary system 600 asillustrated in FIG. 6. In FIG. 6, system 600 illustrates a SORTD schemethat can be employed in a wireless communication system using LTE orLTE-A equipment or another appropriate wireless communicationtechnology.

Referring to FIG. 6, a wireless device can transmit a message on the ULsuch as an ACK/NAK on a PUCCH format 1a/1b message. It is important torecognize that different UL physical channels, such as PUCCH withformats 1/1a/1b, PUCCH with formats 2/2a/2b and PUSCH, use differentmodulation techniques that may require each UL physical channeltransmission to use a different transmit diversity scheme to achieveimproved performance. In FIG. 6, a message such as ACK/NAK can be inputto a modulator 601. Modulator 601, for instance, may apply quadraturephase shift keying (“QPSK”) modulation, binary phase shift keying(“BPSK”), or any other form of modulation. The modulated symbols can beinput to a spreading logic 602. An index 609 for selecting an orthogonalresource 605 for spreading a message can be derived using the index ofthe first CCE 608 of the PDCCH 607 in which the corresponding PDSCH isscheduled. Index 609 can be input to spreading logic 602 and can be usedto select orthogonal resource 605, which can be composed of a firstspreading sequence 606 a and a second spreading sequence 606 b.Spreading logic 602 can apply first spreading sequence 606 a and secondspreading sequence 606 b to the modulated symbols. The modulated symbolsafter spreading can be input to a transmitter 603. Transmitter 603 canplace modulated symbols after spreading into an RB for transmissionusing an antenna 604 to a base station. In one example, a PUCCH format 1message used for a scheduling request may bypass modulator 601, be inputto spreading logic 602, and input to transmitter 603 for UL transmissionusing antenna 604.

LTE-A Release 10 may support multiple transmit antennas on the UL. Tosupport transmit diversity such as SORTD for LTE-A equipment can requiremultiple orthogonal resources. In accordance with one aspect, thewireless transmission of control information can be conducted using atransmit diversity scheme such as a system 700 as illustrated in FIG. 7.In this embodiment, system 700 illustrates a SORTD scheme that can beemployed in a system using LTE or LTE-A equipment or another appropriatewireless communication technology. SORTD may be applied, for instance,to a modulated PUCCH format 1/1a/1b message for improved communicationperformance while maintaining low PAPR. In system 700, orthogonalresource spreading over each transmit antenna is achieved by mappingindices of those of CCEs in a PDCCH to the orthogonal resources used forPUCCH ACK/NAK transmission.

Referring to FIG. 7, a message such as a PUCCH format 1/1a/1b messagecan be input to a modulator 701. Modulator 701, for instance, may applyquadrature phase shift keying (“QPSK”) modulation, binary phase shiftkeying (“BPSK”), or any other form of modulation. The modulated symbolscan be input to a spreading logic 702 a and 702 b. A first index 710 afor selecting an orthogonal resource 705 a for spreading a message canbe derived using the index of a first CCE 708 of a PDCCH 707 in whichthe corresponding PDSCH is scheduled. A second index 710 b for selectingan orthogonal resource 705 b for spreading a message can be derived byselecting and using the index of a second CCE 709 of PDCCH 707. Firstindex 710 a and second index 710 b can be input to spreading logic 702 aand 702 b for selection of a first orthogonal resource 705 a and asecond orthogonal resource 705 b, respectively. First orthogonalresource 705 a can be composed of a first spreading sequence 706 a and asecond spreading sequence 706 b, or a first pre-calculated orconcurrently generated combined sequence comprising first spreadingsequence 706 a and second spreading sequence 706 b. Second orthogonalresource 705 b can be composed of a third spreading sequence 706 c and afourth spreading sequence 706 d, or a second pre-calculated orconcurrently generated combined sequence comprising third spreadingsequence 706 c and fourth spreading sequence 706 d. Spreading logic 702a can apply first spreading sequence 706 a and second spreading sequence706 b to the modulated symbols, or can apply the first pre-calculated orconcurrently generated combined sequence comprising first spreadingsequence 706 a and second spreading sequence 706 b. In parallel,spreading logic 702 b can apply third spreading sequence 706 c andfourth spreading sequence 706 d to the modulated symbols, or can applythe second pre-calculated or concurrently generated combined sequencecomprising third spreading sequence 706 c and fourth spreading sequence706 d. The modulated symbols after spreading can be input totransmitters 703 a and 703 b and transmitted using antennas 704 a and704 b, respectively.

When there is a plurality of CCEs in PDCCH and there are more CCEs thanthe number of orthogonal resources required, then the index of each CCEcan be used as an index to an orthogonal resource used for spreading thePUCCH ACK/NAK. In accordance with one aspect, the mapping of orthogonalresources for transmit diversity in a wireless communication system canbe conducted using various mapping methods such as methods 800 a, 800 b,800 c and 800 d as illustrated in FIG. 8. In these embodiments, methods800 a, 800 b, 800 c and 800 d illustrate the mapping of indices ofselected CCEs to orthogonal resources that can be employed in a systemusing LTE or LTE-A equipment or another appropriate wirelesscommunication technology. Methods 800 a, 800 b, 800 c, 800 d or thelike, if known a priori by both a wireless device and a base station maynot require further communication between the wireless device and thebase station to implement such methods. Alternatively, the wirelessdevice and the base station may exchange communication to select one ormore mapping methods such as methods 800 a, 800 b, 800 c, 800 d, or thelike.

Referring to FIG. 8, method 800 a shows a plurality of CCEs on a PDCCH.A base station can assign PDCCH resource 802 a to a wireless device.PDCCH resource 802 a can include a plurality of CCEs. The wirelessdevice can determine the location of a first CCE 808 a of PDCCH resource802 a. The location of first CCE 808 a can be one of a plurality of CCEscontained in PDCCH resource 802 a. The wireless device may use, forinstance, blind detection to determine the location of first CCE 808 a.A second CCE 809 a can be selected as the CCE adjacent and consecutiveto first CCE 808 a logically. A first index 810 a and a second index 811a can be derived from indices of first CCE 808 a and second CCE 809 aand can be used to select a first orthogonal resource 705 a of aspreading logic 702 a and a second orthogonal resource 705 b of aspreading logic 702 b for use in orthogonal spreading of a message,respectively.

Referring to FIG. 8, method 800 b shows a plurality of CCEs on a PDCCH.A base station can assign a PDCCH resource 802 b to a wireless device.PDCCH resource 802 b can include a plurality of CCEs. The wirelessdevice can determine the location of a first CCE 808 b of PDCCH resource802 b. The location of first CCE 808 b can be one of a plurality of CCEscontained in PDCCH resource 802 b. The wireless device may use, forinstance, blind detection to determine the location of first CCE 808 b.A second CCE 809 b can be selected as a fixed span of CCEs from firstCCE 808 b. For example, method 8006 shows second CCE 809 b as a fixedspan of two CCEs from first CCE 808 b. A first index 810 b and a secondindex 811 b can be derived from indices of first CCE 808 b and secondCCE 809 b and can be used to select a first orthogonal resource 705 a ofa spreading logic 702 a and a second orthogonal resource 705 b of aspreading logic 702 b for use in orthogonally spreading a message,respectively.

Referring to FIG. 8, method 800 c shows a plurality of CCEs on a PDCCH.A base station can assign a PDCCH resource 802 c to a wireless device.PDCCH resource 802 c can include a plurality of CCEs. The wirelessdevice can determine the location of a first CCE 808 c of PDCCH resource802 c. The location of first CCE 808 c can be one of a plurality of CCEscontained in PDCCH resource 802 c. The wireless device may use, forinstance, blind detection to determine the location of first CCE 808 c.A second CCE 809 c can be selected as the last CCE in PDCCH resource 802c relative to first CCE 808 c. For example, method 800 c shows first CCE808 c as the first CCE of PDCCH resource 802 c and second CCE 809 c asthe last CCE of PDCCH resource 802 c. A first index 810 c and a secondindex 811 c can be derived from indices of first CCE 808 c and secondCCE 809 c, and used to select a first orthogonal resource 705 a of aspreading logic 702 a and a second orthogonal resource 705 b of aspreading logic 702 b for use in orthogonal spreading of a message,respectively.

Referring to FIG. 8, method 800 d shows a plurality of CCEs on a PDCCH.A base station can assign a PDCCH resource 802 d to a wireless device.PDCCH resource 802 d can include a plurality of CCEs. The wirelessdevice can determine the location of a first CCE 808 d of PDCCH resource802 d. The location of first CCE 808 d can be one of a plurality of CCEscontained in PDCCH resource 802 d. The wireless device may use, forinstance, blind detection to determine the location of first CCE 808 d.The selection of a second CCE 809 d is constrained by and must satisfy

${{m\mspace{14mu} {mod}\mspace{11mu} \left( \left\lfloor \frac{M}{N} \right\rfloor \right)} = 0},$

where m is the index of second or successive CCEs 809 d, M is the numberof CCEs in PDCCH resource 802 d, and N is the number of orthogonalresources required. In one embodiment, the number of orthogonalresources required corresponds to the number of antennas of a wirelessdevice. For m=0, the index corresponds either to a specific CCE in theoverall PDCCH search space or to the first CCE of the PDCCH beingconsidered. For example, for M=8 and N=2, second CCE 809 d would beselected as m=4, the fourth CCE of PDCCH resource 802 d relative tofirst CCE 808 d of PDCCH resource 802 d. A first index 810 d and asecond index 811 d can be derived from indices of first CCE 808 d andsecond CCE 809 d and used to select a first orthogonal resource 705 a ofa spreading logic 702 a and a second orthogonal resource 705 b of aspreading logic 702 b for use in orthogonal spreading of a message,respectively.

It may also be desirable to give preference to or only use orthogonalresources that are within a given RB for PUCCH. In accordance with oneaspect, the mapping of orthogonal resources for transmit diversity in awireless communication system can be further constrained using variousmapping processes such as a method 900, as illustrated in FIG. 9. Inthis embodiment, method 900 illustrates limiting the mapping of indicesof selected CCEs to orthogonal resources within a particular RB forPUCCH that can be employed in a system using LTE or LTE-A equipment oranother appropriate wireless communication technology.

Referring to FIG. 9, method 900 shows a PUCCH wrap-around method, wherethe PUCCH resource indexing can be wrapped around using the following:

m mod (N_(i)),

where m is the PUCCH resource index and N_(i) is the number oforthogonal resources per PUCCH RB. For example, method 900 shows a firstPUCCH orthogonal resource 908 as the last element of a PUCCH RB 901. Ifthe next successive element of PUCCH RB 908 were selected as the secondPUCCH orthogonal resource, then the second PUCCH orthogonal resourcewould be associated with a different PUCCH RB. Instead, the PUCCHresource index is wrapped around to the start of PUCCH RB 901, and asecond PUCCH orthogonal resource 911 is selected as the first element ofPUCCH RB 901.

In another embodiment, the selection of the second CCE can beconstrained by and satisfy:

Starting CCE index+(offset_(i)) mod (N_(x)),

where offset_(i) is the CCE offset from the first CCE and N_(x) is thenumber of CCEs whose derived PUCCH resources are in the same RB as thatderived from the first CCE, which would be used to derive the ith PUCCHresource using, for instance, method 800 a, 800 b, 800 c or 800 d.

Referring to FIG. 10, a method 1000 shows six CCEs composing a PDCCHresource 1002. In one example, the first and sixth CCEs could be used toderive two PUCCH resources using two indices. If the derived PUCCHresources from the first three CCEs of PDCCH resource 1002 correspond toa PUCCH RB 1020, while derived PUCCH resources from the last three CCEscorrespond to another PUCCH RB, then a third CCE 1012 may be used toderive a second index 1011. In this way, method 1000 can allow for theuse of PUCCH resources from the same PUCCH RB.

If the wrapped around CCE is being used by a different wireless deviceresulting in two wireless devices transmitting on the same CCE, then acollision may occur. In such circumstance, for example, to avoid acollision, a wireless device may use the next available CCE. Suchsituations may occur when mapping CCEs of a PDCCH to PUCCH resourcescorresponding to different PUCCH RBs. In another embodiment, anotheralternative is to use CCEs corresponding to PUCCH resources in anotherPUCCH RB as described by a method 1100, as illustrated in FIG. 11.Method 1100 can allow for PUCCH resources to be derived from CCEs of aPDCCH that correspond to the same PDCCH RB.

Referring to FIG. 11, initially a first CCE 1108 can be selected in afirst PUCCH RB 1120. Instead of selecting a second CCE from first PUCCHRB 1120, the first CCE can be re-selected as a first CCE 1109 and cancorrespond to a second PUCCH RB 1130. A second CCE 1112 can be selectedand can reside within the same PUCCH RB as first CCE 1109. A first index1110 and a second index 1111 can be derived from indices of first CCE1109 and second CCE 1112 and can be used to select first orthogonalresource 705 a of spreading logic 702 a and second orthogonal resource705 b of spreading logic 702 b for use in orthogonal spreading of amessage, respectively.

When the number of CCEs in a PDCCH are limited to less than the numberof orthogonal resources required, then an alternative method may berequired. In one embodiment, a base station can assign a wireless devicea PDCCH that has at least the same number of CCEs as orthogonalresources required to support transmit diversity of the wireless device.

In another embodiment, the PDCCH aggregation level can be increased bylowering the coding rate of PDCCH to increase the number of CCEs. Theindex of such additional CCEs can be used to derive additionalorthogonal resources for a wireless device.

In another embodiment, a base station can allocate reserved CCEs andgrant access to such reserved CCEs. Referring to FIG. 12, a method 1200shows a plurality of CCEs on a PDCCH 232. The base station can increasethe PDCCH aggregation level to provide a wireless device with anadditional CCE 1209 to allow the wireless device to derive an additionalorthogonal resource to support, for instance, two antennas for transmitdiversity. A first index 1210 and a second index 1211 can be derivedfrom indices of a first CCE 1208 and a second CCE 1209, and used toselect a first orthogonal resource 705 a of a spreading logic 702 a anda second orthogonal resource 705 b of a spreading logic 702 b for use inorthogonal spreading of a message, respectively.

In another embodiment, a wireless device may decrease the number oforthogonal resources and fallback to a lower order of transmit diversityto match the number of CCEs assigned to the wireless device by a basestation. Further, antenna virtualization can be used by the wirelessdevice to map one or more physical antennas to one or more virtualantenna. For example, a wireless device can be capable of using fourphysical antennas for transmit diversity. However, a base station mayallocate only two CCEs in a PDCCH for the wireless device. In thisscenario, the wireless device may map the four physical antennas to twovirtual antennas. In such alternative, compensation of transmit powermay be required due to the use of antenna virtualization. To compensate,the base station may provide the wireless device with transmit powercontrol (“TPC”) commands, which allows the wireless device to change itstransmit power by specific positive or negative increments. In anothermethod of compensation, a base station can communicate to a wirelessdevice a predefined set of user-specific power adjustments for eachconfigured PUCCH transmission scheme. The wireless device can performopen-loop transmit power control of PUCCH using the predefined set ofuser-specific power adjustments associated with the particularconfigured PUCCH transmission process.

In another embodiment, a base station can communicate to a wirelessdevice the location of unassigned CCEs within the PDCCH for thatsubframe. For empty CCEs located elsewhere within the PDCCH, the basestation may use, for example, a downlink control information (“DCI”)addressed to another wireless device's common radio network temporaryidentifier (“C-RNTI”), or a shared DCI addressed to a common SORTD-RNTIthat implicitly or explicitly provides information regarding unassignedCCEs within the PDCCH. Alternatively, an additional field within the DLgrant DCI can be used by a base station and a wireless device toindicate the PUCCH resource indices.

It may be required to maintain the same mapping rule as specified in LTERelease 8, whereas the index of the first CCE in PDCCH is mapped to thefirst orthogonal resource of PUCCH. In one embodiment, offsets from theindex of a first CCE in PDCCH can be used to derive additionalorthogonal resources. Such offsets can be fixed or communicated, forinstance, dynamically or statically by a base station to a wirelessdevice. For example, the base station can communicate an offset to thewireless device using the PDCCH, if such PDCCH is transmitted with thefirst CCE of the PDCCH. For a situation where a collision may occur, thebase station may reassign the other wireless device, with which acollision may occur, to its next possible starting CCE of the PDCCH. Forexample, a method 1300, as illustrated in FIG. 13, shows a plurality ofCCEs on a PDCCH. A wireless device is assigned a first CCE 1308 of thePDCCH, which only contains one CCE. Another wireless device is assigneda CCE 1309. If the offset used by the wireless device corresponds to asecond CCE 1309, which is being used by the other wireless device, thena potential collision may occur. To avoid such collision, the basestation can move the CCE of the other wireless device from CCE 1309 to aCCE 1312. The wireless device can then use second CCE 1309.

In another embodiment, a base station can broadcast an over-provisionedPUCCH space reserved for persistent ACK/NAK and scheduling requestindicator (“SRI”). For LTE Release 8, the over-provisioned PUCCH spacemay not be used. However, the base station and a wireless device mayknow the location of the PUCCH resource reserved for dynamic ACK/NAK.For LTE Release 10, a wireless device may use the over-provisioned spacefor persistent ACK/NAK and SRI for sending dynamic ACK/NAK on PUCCH,while applying either a two-transmit or four-transmit diversity system.The base station can provide an LTE-A-capable wireless device with thebeginning boundary of the dynamic ACK/NAK PUCCH resource. In anotherembodiment, a similar mapping can be defined for mapping the PDCCH CCEindex to the PUCCH index within this dynamic ACK/NAK PUCCH resourcespace.

In another embodiment, the orthogonal resources can be organized intoone or more subsets of orthogonal resources. In one example, a wirelessdevice using two antennas can access subsets of orthogonal resourcescomprising a first orthogonal resource for a first antenna and a secondorthogonal resource for a second antenna. The same mapping rule asdescribed by LTE Release 8 may be used to map the subsets of orthogonalresources, whereas the index may have a one-to-one mapping with thefirst CCE of the PDCCH. In another embodiment, the organization of thesubsets of orthogonal resources may be determined using a formula thatis known by both a base station and a wireless device.

It is important to recognize that the aforementioned embodiments can beapplied to other communication formats such as PUCCH format 2/2a/2b andMIMO, coordinated multi-point (“CoMP”), and carrier aggregation (“CA”).

In LTE Release 8, three orthogonal sequences can be used fortime-direction covering, and twelve cyclic-shifted sequences can be usedfor frequency-direction covering. In total, a maximum of thirty-sixPUCCH orthogonal resources may be supported in each PUCCH RB for formats1a and 1b. The limited number of PUCCH orthogonal resources may limitthe number of wireless devices multiplexed on one PUCCH RB. Inaccordance with one aspect, a transmit diversity system can usequasi-orthogonal resources to increase the number of orthogonalresources available to a system such as a system 1400 as illustrated inFIG. 14.

In FIG. 14, a modulated message can be input to a plurality of spreadinglogic 1404 a, 1404 b and 1404 c. The plurality of spreading logic 1404a, 1404 b and 1404 c can access an orthogonal resource pool 1401 toobtain orthogonal resources, and a quasi-orthogonal resource pool 1402to obtain quasi-orthogonal resources. The plurality of spreading logic1404 a, 1404 b and 1404 c can apply to the modulated message theorthogonal resources of orthogonal resource pool 1401 and thequasi-orthogonal resources of quasi-orthogonal resource pool 1402, or apre-calculated or concurrently-generated combination of orthogonalresources of orthogonal resource pool 1401 and quasi-orthogonalresources of quasi-orthogonal resource pool 1402. The modulated messageafter spreading can be transmitted from a plurality of antennas 1405 a,1405 b and 1405 c. The quasi-orthogonal resources of quasi-orthogonalresource pool 1402 can be generated using various approaches known tothose having ordinary skill in the art.

In another embodiment, the orthogonal resources of an orthogonalresource pool 1401 may be as specified in LTE Release 8 and can be usedas the orthogonal resource for transmitting PUCCH from a first antenna1405 a. The quasi-orthogonal resources of a quasi-orthogonal resourcepool 1402 may then be applied to the modulated message by a second and athird spreading logic 1404 b and 1404 c and transmitted from antennas1405 b and 1405 c, respectively.

In another embodiment, a wireless device may use the quasi-orthogonalresources only when the number of CCEs of PDCCH is less than the numberof transmit antennas available to the wireless device.

In another embodiment, a wireless device may exclusively use thequasi-orthogonal resources for all of its transmit antennas.

Transmit diversity systems, such as SORTD, may not be optimal,applicable or realizable in certain situations. Therefore, there may bea need to provide a plurality of transmit diversity schemes dependent onthe specific circumstances. In one embodiment, three or more transmitdiversity modes can be used for a wireless device with four antennas.For example, one mode could use a SORTD system for two antennas, such assystem 700. A second mode could use a SORTD system for four antennas,such as system 700. A third mode could use a single antennatransmission, such as system 600.

In another embodiment, a base station can statically or dynamicallyconfigure a wireless device for any multitude of transmit diversitymodes based on, for instance, the quality of service (“QoS”) of thewireless communication between the base station and the wireless device,the availability of network resources, or other conditions. QoS factors,for example, may include word error rate (“WER”), bit error rate(“BER”), block error rate (“BLEW”), signal strength, signal to noiseratio (“SNR”), signal to interference and noise ratio (“SINR”), andother factors. For example, a base station can configure a wirelessdevice to use a single antenna transmission such as system 600 when thewireless device has an adequate QoS. Alternatively, a base station canconfigure a wireless device to use two or more antennas in transmitdiversity mode when the wireless device has a lower QoS, for instancewhen the wireless device is at a cell edge.

In order for a base station to statically or dynamically configuretransmit diversity modes for a wireless device may require explicitsignaling between them. In accordance with one aspect, the communicationof transmit diversity configuration information in a wirelesscommunication system can use method 1500 as illustrated in FIG. 15. Inone embodiment, method 1500 illustrates the communication between a basestation 1502 and a wireless device 1501 in configuring transmitdiversity modes for wireless device 1501.

In method 1500, wireless device 1501 initially can use a single antennatransmission for PUCCH. While in single transmission mode, wirelessdevice 1501 can send an UL random access channel (“RACH”) message tobase station 1502, for instance, to request base station 1502 toconfigure the transmit diversity mode of wireless device 1501, asrepresented by 1510. Base station 1502 can confirm the RACH 1505 sent bywireless device 1501, as represented by 1515. Wireless device 1501 cansend its number of transmit antennas to base station 1502, asrepresented by 1520. In response, base station 1502 can send ahigher-layer message to configure the transmit diversity mode ofwireless device 1501, as represented by 1530. Wireless device 1501 cansend an acknowledgement message, as represented by 1540. Wireless device1501 is now configured using its assigned transmit diversity mode andcan send, for instance, a PUCCH message using its configured transmitdiversity mode, as represented by 1550.

Method 1500 can also be applied to other channel formats such as PUSCHand PUCCH formats 2/2a/2b. It is important to note that other channelformats may require other transmit diversity modes. For example, thetransmission modes for PUSCH may be a pre-coding based SM mode, aSTBC-based mode, a single antenna transmission mode, or any other modeor combination of modes. Further, the transmission modes for PUCCHformats 2/2a/2b may use STBC or STBC-based mode, single antennatransmission mode, or any other mode or combination of modes.

For additional orthogonal resources for transmit diversity, such asSORTD, the assignment of orthogonal resources can be communicated usinghigher-layer signaling. In LTE Release 8, for PUCCH format 1 and PUCCHformats 1a/1b for semi-persistent scheduling (“SPS”) transmission, theorthogonal resources may be assigned using higher-layer signaling. Inone embodiment, when the DCI format indicates a semi-persistent DLscheduling activation, the TPC command for the PUCCH field can be usedby higher layers to provide an index to one of four PUCCH resourceindices, with the orthogonal resource mapping defined by method 1600.Further, the TPC command for PUCCH field can map to multi-dimensionalorthogonal resources for the PUCCH with the orthogonal resource mappingdefined by method 1700. In FIG. 16, method 1600 shows the mapping oforthogonal resources for the PUCCH when a wireless device uses oneantenna. In FIG. 17, method 1700 shows the mapping of orthogonalresources for the PUCCH when a wireless device uses two antennas, forinstance, in a SORTD mode.

In another embodiment, after the TPC command for the PUCCH field is usedto derive the PUCCH resource for the first antenna of a wireless device,a pre-configured formula or mapping table such as fixed or configurableoffsets can be used to derive PUCCH resources for the remainingantennas.

As discussed earlier, it is desirable to reduce the number of transmitcollisions between wireless devices in a wireless communication system.The probability of a transmit collision will depend on the transmitdiversity mode being used by a wireless device. Since a base station cancontrol the allocation of PUCCH resources amongst the wireless devicescontrolled by the base station, the base station can manage thescheduling and allocation of PUCCH resources to mitigate the probabilityof transmit collisions. The base station can use a multitude of metricsto manage the scheduling and allocation of PUCCH resources. For example,a base station can use metrics associated with the number of PUCCHresource collisions, the number of PUCCH resource collisions forwireless devices using only one PUCCH resource, the number of PUCCHresource collisions for wireless devices using a plurality of PUCCHresources. Based on these metrics, the base station may configure itssystem parameters to, for instance, eliminate the probability ofcollision for a wireless device using one PUCCH resource, reduce theprobability of collisions to no more than one collision for a wirelessmobile using two PUCCH resources, reduce the probability of collisionsto no more than two collisions for a wireless mobile using four PUCCHresources, other requirement, or any combination thereof.

In another embodiment, due to different possible PA configurations forLTE-A UEs, (for example, for 2-tx antennas at the UE, the following UEPA configurations should be supported: (1) 20 dBm+20 dBm, (2) 23 dBm+23dBm, and (3) 23 dBm+x, where x≦23 dBm), there are still some open issueson how to configure the single antenna port mode for UEs with differentPA configurations. Currently, there are two possible alternatives toconfigure single antenna port mode for a UE, either through usingantenna turning-off vector in the codebook, or through antennavirtualization. The first alternative would allow configuration ofsingle antenna port mode by turning off one or multiple physicalantennas, and this could be done either dynamically or semi-statically.The second alternative may require transmitting from all the physicalantennas resulting in the appearance of single antenna transmissionthrough antenna virtualization, which could be configured throughhigher-layer signaling, and therefore lead to semi-static configurationof such mode.

If a UE has a 2×20 dBm PA configuration, then the first alternative maynot be feasible for configuring its single antenna mode as simplyturning off one physical antenna (and one PA) would not satisfy therequirement of total transmit power of 23 dBm being available, and thatwould certainly affect the UE's coverage. Therefore, the secondalternative seems to be the preferable way to configure single antennamode for such kind of UE. Similarly for a UE with 4 transmit antennasand a 4×17 dBm PA configuration, antenna virtualization could be used toachieve single antenna mode by transmitting simultaneously from all 4physical antennas.

To achieve this, a UE may need to inform the eNB about its PAconfiguration. Such PA configuration could be either part of the UEcategory or signaled during the UE's initial access to the network. Thenthe eNB could decide what method it will use to configure single antennamode for such UE. For those UEs whose individual PAs may not be able totransmit with an individual transmit power of 23 dBm, the eNB couldchoose to configure single antenna mode through antenna virtualization,and this could be done semi-statically. For other types of PAconfigurations where each individual PA could transmit at 23 dBm, theeNB could either configure single antenna mode through the use ofturning-off vectors in the codebook or through antenna virtualizationconfigured by higher-layer signaling. For a UE with 4 transmit antennas,the turning-off vectors in the codebook may support turning off antennasby pairs; in this case, single antenna transmission could be achieved byapplying antenna virtualization on the remaining transmit antennas.

In another embodiment, the eNB may configure single antenna transmissionmode, for example, using higher-layer signaling. If that is the case,the UE may not need to report its PA configuration, but depending on theUE's PA configuration, the UE could choose its own method for achievingsingle antenna mode by either turning off some physical antennas andtransmitting from a single physical antenna or performing antennavirtualization from a reduced set of physical antennas, or by usingantenna virtualization across all physical antennas, and at the sametime ensuring that the maximum transmit power requirement of 23 dBm isstill satisfied.

As the single antenna mode could be realized differently at the UE, thepower headroom reporting could be generated differently at the UE eventhough a single power headroom offset could be reported to the eNB. Ifone physical antenna is used to realize the single antenna mode, thepower headroom on that single transmit antenna could be reported. Ifmultiple physical antenna transmissions are used to realize singleantenna mode through antenna virtualization, the single power headroomreported could be derived based on the power headroom on each individualPA; one example would be to use the combined power headroom acrossphysical transmitting antennas.

If the UE is permitted to transmit in single antenna mode in more thanone way, the amount of power it can transmit could vary. For example, inconfiguration (3) above, the maximum power if the UE transmits on onephysical antenna may be 23 or x dBm. The UE may choose which antenna ittransmits on based on current channel conditions, such as if one antennais weaker than another, which for example could be caused by the user'shand being close to the antenna.

Since the maximum amount of transmit power in single antenna mode canvary between multi-antenna and single-antenna modes, the PA headroom canvary between single antenna mode and multi-antenna mode. Therefore,additional signaling may be required when the UE is transmitting inmultiple-antenna mode to inform eNB of what the PA headroom would be insingle antenna mode. This signaling could include a PA power offsetindicating the difference (in dB) between multi-antenna power (or PApower headroom) and single antenna transmit power (or PA power headroom)under current channel conditions.

The use of this PA power offset signaling could help eNB to decide if itshould switch the UE to single antenna mode. If the UE has insufficientPA headroom in single antenna mode, eNB could decide to keep the UE inmulti-antenna mode.

As the realization of a single antenna port mode at a UE may bedifferent, for instance, by using antenna virtualization or a singlephysical antenna, transmitting a sounding reference signal from a singleantenna port may not be the same or similar to transmitting a soundingreference signal from any single physical antenna. For example, a UE canrealize single antenna port mode by transmitting the signal from asingle physical antenna, in this case, transmit a sounding referencesignal from this physical antenna is the same or similar to transmittingthe sounding reference signal from a single antenna port. In anotherexample, a UE using antenna virtualization to realize a single antennaport can simultaneously or at about the same time transmit from aplurality of physical antennas, in this case, transmitting soundingreference signals from any physical antenna is not equivalent totransmitting the sounding reference signal from a single antenna port.

It is important to recognize that the eNB may not know how the singleantenna port mode is realized at the UE. In one embodiment, a soundingreference signal port can be defined for a sounding reference signaltransmitted using single antenna port mode. In another embodiment, a setof sounding reference signal ports can be defined for the soundingreference signal transmitted from each physical antenna. In anotherembodiment, a sounding reference signal port can be defined for asounding reference signal transmitted using single antenna port mode,and another set of sounding reference signal ports can be defined forthe sounding reference signal transmitted from each physical antenna.For example, a UE with four physical transmit antennas can have fourreference sounding signal ports defined as x1, x2, x3, and x4 forsounding reference signals transmitted from each of the four physicaltransmit antennas, while another sounding reference signal port definedas x5 for a sounding reference signal transmitted from a single antennaport. It is important to recognize that such embodiments can make thesounding reference signal transmission independent of UE implementationfor single antenna port mode.

In another example, a UE with four physical transmit antennas, which canbe configured to simultaneously transmit from four transmit antennas, orfrom two transmit antennas, or from one transmit antenna (singleantenna), can specify sounding reference signal ports defined as x1, x2,x3, and x4 for a sounding reference signal transmitted from each of thefour physical transmit antennas. Further, additional sounding referencesignal ports defined as x5 and x6 can be specified for a soundingreference signal transmitted using each of the two transmit antennaports when it is configured with two transmit antenna ports. Finally,another sounding reference signal port defined as x7 can be specifiedfor a sounding reference signal transmitted using the one transmitantenna port (single antenna port) when it is configured with singleantenna port.

In another embodiment, the type of sounding reference signal such as anaperiodic sounding reference signal or a periodic sounding referencesignal can be specified for each antenna. In another embodiment, thetype of sounding reference signal such as an aperiodic soundingreference signal or a periodic sounding reference signal can bespecified as a different sounding reference signal port. For example, aUE with four physical transmit antennas can specify four soundingreference signal ports defined as x1, x2, x3, and x4, which can be usedfor transmitting aperiodic sounding reference signals from each of thefour physical antennas. Further, another four sounding reference signalports defined as x5, x6, x7, and x8 can be specified for periodicsounding reference signals transmitted from each of the four physicalantennas.

In another embodiment, additional antenna ports can be specified for thetransmission of a PUSCH signal. For example, two antenna ports or asingle antenna port can be configured for the transmission of a PUSCHsignal, additional sets of sounding reference signal ports can bedefined, one for transmitting aperiodic sounding reference signals andone for transmitting periodic sounding signals. For example, a set ofsounding reference signal ports defined as x9, x10, and x11 can bespecified for aperiodic sounding reference signals, where ports x9 andx10 can be used to transmit aperiodic sounding reference signals foreach transmit antenna when two transmit antenna ports are configured andport x11 is used to transmit aperiodic sounding reference signal forsingle antenna port transmission. Similarly, for periodic soundingreference signals, a set of sounding reference signal ports defined asx12, x13, and x14 can be specified, where ports x12 and x13 can be usedto transmit periodic sounding reference signals for each transmitantenna when two transmit antenna ports are configured and port x14 isused to transmit periodic sounding reference signal for a single antennaport.

In another embodiment, different types of sounding reference signalports can be used to transmit a sounding reference signal for differentantenna configurations. For example, a periodic sounding referencesignal port can be used to transmit a sounding reference signal forsingle antenna port mode, while aperiodic sounding reference signalports can be used to transmit sounding reference signals for differentphysical antennas.

In another embodiment, the sounding reference signal ports can bere-used for different antenna configurations. For example, if a UEsupports four physical transmit antennas, then four sounding referencesignal ports can be defined as x1, x2, x3, and x4. When the UE isconfigured with single antenna port mode, the sounding reference signalport x1 can be used for sounding reference signal transmission. If theUE is configured with two antenna ports, then the sounding referencesignal ports x1 and x2 can be used for sounding reference signaltransmission from each antenna. If the UE is configured with fourantenna ports, then the sounding reference signal ports x1, x2, x3, andx4 can be used for sounding reference signal transmission from eachantenna.

Having shown and described exemplary embodiments, further adaptations ofthe methods, devices, and systems described herein may be accomplishedby appropriate modifications by one of ordinary skill in the art withoutdeparting from the scope of the present disclosure. Several of suchpotential modifications have been mentioned, and others will be apparentto those skilled in the art. For instance, the exemplars, embodiments,and the like discussed above are illustrative and are not necessarilyrequired. Accordingly, the scope of the present disclosure should beconsidered in terms of the following claims and is understood not to belimited to the details of structure, operation, and function shown anddescribed in the specification and drawings.

As set forth above, the described disclosure includes the aspects setforth below.

1. A method for the transmission of information in a wirelesscommunication system, comprising: determining by a wireless device aconfiguration of a plurality of power amplifiers to achieve a singleantenna transmission mode; amplifying a signal by said wireless deviceusing said configuration of said plurality of power amplifiers to form aplurality of amplified signals; simultaneously transmitting at or aboutthe same time by said wireless device to a base station said pluralityof amplified signals from a plurality of physical antennas, wherein saidplurality of physical antennas are coupled to said configuration of saidplurality of power amplifiers; and wherein the measured transmit powerfrom the totality of said plurality of physical antennas is about thesame as the required transmit power using said single antennatransmission mode.
 2. The method of claim 1, further comprising: sendingfrom said wireless device to said base station said configuration ofsaid power amplifiers of said wireless device.
 3. The method of claim 1,further comprising: receiving by said wireless device from said basestation said single antenna transmission mode.
 4. The method of claim 1,wherein said determining by said wireless device a configuration of aplurality of power amplifiers to achieve a single antenna transmissionmode further comprising: enabling, disabling, or both a portion of saidplurality of power amplifiers to achieve about the same transmit poweras said single antenna transmission mode.
 5. The method of claim 1,further comprising: determining by said wireless device a power headroomoffset of said configuration of said plurality of power amplifiers bycombining the power headroom from each power amplifier of saidconfiguration of power amplifiers; and sending by said wireless deviceto said base station said power headroom offset.
 6. The method of claim1, wherein said determining by said wireless device a configuration of aplurality of power amplifiers to achieve a single antenna transmissionmode further comprising: enabling, disabling, or both a portion of saidplurality of power amplifiers using the channel conditions received atsaid plurality of physical antennas.
 7. The method of claim 1, furthercomprising: determining by said wireless device a power headroom offsetas the difference between the power headroom of said configuration ofsaid plurality of power amplifiers used to achieve said single antennatransmission mode and the power headroom of a single power amplifierused to perform said single antenna transmission mode; and sending bysaid wireless device to said base station said power headroom offset. 8.A method for operating a wireless communication system, the methodcomprising: receiving, by a wireless device in the system, informationon a sounding reference signal port to support the transmission of asounding reference signal using a single antenna port mode; receiving,by the wireless device, information on a set of sounding referencesignal ports to support the transmission of said sounding referencesignal using one or more of a plurality of physical antennas; selecting,by the wireless device, one or more of said sounding reference signalports; and transmitting by the wireless device to a base station in thesystem, said sounding reference signal using said selected one or moreof said sounding reference signal ports.
 9. The method of claim 8,further comprising: defining by said wireless device another set ofsounding reference signal ports to support the transmission of saidsounding reference signal using a portion of said plurality of physicalantennas.
 10. The method of claim 8, wherein said sounding referencesignal can be aperiodic or periodic.
 11. The method of claim 8, whereinsaid sounding reference signal ports are defined separately for anaperiodic sounding reference signal, a periodic sounding referencesignal, or both.
 12. The method of claim 8, wherein a periodic soundingreference signal port, an aperiodic sounding reference signal port, orboth is specified to transmit said sounding reference signal using saidsingle antenna port mode; and a plurality of aperiodic soundingreference signal ports, a plurality of periodic sounding referencesignal ports, or both are specified to transmit said sounding referencesignals for said plurality of physical antennas.
 13. The method of claim8, wherein one or more of said sounding reference signal ports can bere-used for other physical antenna configurations.
 14. The method ofclaim 8, wherein said selecting one or more of said sounding referencesignal ports further comprising: selecting by said wireless device oneor more of said sounding reference signal ports.
 15. The method of claim8, wherein said selecting one or more of said sounding reference signalports further comprising: selecting by said wireless device one or moreof said sounding reference signal ports; and sending from said wirelessdevice to said base station said selection of one or more of saidsounding reference signal ports.
 16. The method of claim 8, wherein saidselecting one or more of said sounding reference signal ports furthercomprising: receiving by said wireless device from said base stationsaid selection of one or more of said sounding reference signal ports.17. The method of claim 8, wherein said single antenna port modeincludes the ability to simultaneously transmit at or about the sametime said sounding reference signal from a plurality of physicalantennas.
 18. A method for operating a base station in a wirelesscommunication system, the method comprising: transmitting, by the basestation, information on a sounding reference signal port to support thetransmission of a sounding reference signal using a single antenna portmode; transmitting, by the base station, information on a set ofsounding reference signal ports to support the transmission of saidsounding reference signal using one or more of a plurality of physicalantennas; and receiving by the base station, a sounding referencesignal, using selected one or more of said sounding reference signalports.
 19. A wireless device comprising: a communication systemconfigured to perform the method of claim
 8. 20. A base stationcomprising: a communication system configured to perform the method ofclaim 18.